Shaft-speed counter.



P. B. SANBORN.

SHAFT SPEED COUNTER.

APPLICATION FILED JULY 30,1908.

1,001,692, Patented Aug. 29, 1911.

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Witnesses, Inventor.

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FRANK B. SANBORN, OF CAMBRIDGE, MASSACHUSETTS.

Specification of Letters Patent.

SHAFT-SPEED COUNTER.

Patented Aug. 29, 1911.

Application filed July 30, 1908. Serial No. 446,129.

To all whom it may concern:

Be it known that I, FRANK B. SANBORN, a citizen of the United States, and a resident of Cambridge, in the county of Middlesex and State of Massachusetts, have invented a new and Improved Shaft-Speed Counter, of which the following is a specification.

My invention relates to a device for count ing the speed of a revolving shaft, axis or spindle; and the objects of my improvements are to provide a device that can be used in an oily center-hole and not slip, one that will have figures that are plainly visible when counting the speed of a shaft that is revolving in either direction, and one that, in its simplest form, will be light enough to be carried in the vest-pocket.

Figure 1 is a top plan view of my invention; Fig. 2, a side elevation with a part of the case for the counting mechanism cut away; Fig. 3, an end. elevation looking from v the left of Fig. 1; and Fig. 4:, an end elevation looking from the right of Fig. 1.

Similar letters refer to similar parts throughout the several views.

The counting mechanism 17 has plainly visible concentric rows of figures which revolve at different, but related speeds thus enabling the eye to detect any variations from uniform motion. The counting mechanism is contained in a generally cylindrical case 15, through which passes the rotatable spindle or axis 12* which is at present constructed solid, and is extended by the hollow tubing 12 which carries at its outward end the rubber or adhesive tip 11. This tip is designed to engage with a center-hole in the end of a shaft, was or spindle; the posslbilitles of sllpping are reduced to a minimum by use of the finger piece 13 which besides being of service for holding the device when counting the revolutions of a shaft, also serves for cleaning the center hole before the rubber tip is inserted therein. It is attached to the case of the counting mechanism at the base 1 1 as shown in Figs. 2 and 3. This method of attachment permits the cover 18 of the case for the counting mechanism to be unscrewed. A shoulder is formed at 16 which receives the longitudinal thrust of the rotatable shaft or axis 12.

Having thus described my invention, I claim as new and desire to secure by Letters Patent 1. A speed-counter provided with a fingerpiece by which it may be held while in use, said finger-piece being a generally triangular member adapted to conform to the center hole of a shaft, and to serve as a centercleaning device.

2. A speed-counter comprising a casing for the counting mechanism, a rotatable spindle connected with the counting mechanism and being provided with a rubber tip for engagement with a centerhole, and a cleaning device carried by the casing and adapted to fit such center-hole.

FRANK B. SANBORN.

Witnesses:

SYLVANUS H. COBB, HUGH H. WELLMAN.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents, Washington, D. G. 

